复杂断块油藏典型井组注采调整方法研究

Injection- production Adjustment of Typical Wellgroup in Complicated Fault-block Reservoirs

针对东辛油田营13断块油藏储层非均质严重、地层倾角大、井网不规则、水驱不均衡的问题,运用非活塞式水驱油理论,综合考虑储层物性非均质和剩余油饱和度非均质等多种因素,以一注多采井组为例,建立了断块油藏新区和高含水期油井产液量的优化方法。计算分析表明,为实现注水开发在平面上的均衡驱替,油井调整产液量时要综合考虑地层倾角、油层厚度以及目前油井含水率等因素的影响。对于垂直构造线方向的一注两采井组,地层倾角越大,高部位与低部位油井产液量的分配比例越大;油井含水率差异越大,低含水井与高含水井产液量的分配比例越大;两侧井区厚层相差越大,油井产液量的分配比例越大;储层渗透率差异对达到均衡驱替所需的油井液量的分配比例影响相对较小。将研究成果应用到营13断块油藏的注采调整中,日产油能力上升至110.3 t/d,综合含水由95.6%降至91.7%,提高采收率2.4%,取得了较好的开发效果。

The development of Ying13 fault- block reservoir in Dongxin Oilfield is featured by strong reservoir heterogeneity,high dip- angle,irregular well- pattern and uneven waterflooding. Based on non- piston waterflooding theory and single injection and multi production wellgroup,the liquid production optimization in new and high- water- cut fault- block reservoirs is established by considering the various factors of reservoir heterogeneity,residual oil saturation heterogeneity,etc. Analysis indicates that the dip- angle,reservoir thickness,current water- cut of production well and other factors must be comprehensively considered in the liquid production optimization to achieve even displacement in the plane during waterflooding development. For the single- injection and dual- productions wellgroup which is perpendicular to tectonic line,the liquid production allocation ratio of the wells in high and low parts increases with the increase of formation dip- angle. The liquid production allocation ratio of the wells with high and low water- cuts increases with the increase of water- cut difference. The liquid production allocation ratio also increases with the increase of reservoir thickness difference in the two different sides of well- block. The reasonable liquid production allocation ratio that achieves even displacement is less dependent on the reservoir permeability difference. This research is applied to the injection- production adjustment of Ying13 fault- block reservoir,the daily oil production capacity is increased to 110. 3 t / d,the composite water- cut is reduced from 95. 6% to 91. 7%,and the oil recovery degree is increased by 2. 4%,which achieved better waterflooding development.